1. Field of the Invention
The present invention relates to a lumbar support device for a vehicle seat, and more particularly, to a lumbar support device which is capable of adjusting its supporting pressure by means of a remote control operation.
2. Description of the Prior Art
Some conventional vehicle seats include a lumbar support device in the lower portion of a seat back which is capable of adjusting its supporting pressure applied to the lumbar portions of a seat occupant in order to reduce the fatigue of the occupant, especially a driver, during long-distance driving.
Such a conventional lumbar support device is arranged such that its support/pressure member is activated by a control/operation mechanism such as a cam mechanism provided at the side portion of the lumbar support device. The control/operation mechanism is operated by an operation handle (3) mounted onto the side surface of a seat back (2) of a seat (1), as shown in FIG. 1. In this type of seat (1), since a reclining device (4) of the seat back (2) is installed at the side portion of the seat (1) with its arm at the side of a movable portion being mounted onto the side surface of the seat back (2), this movable-portion-side arm will transversely correspond to the lumbar support device. Therefore, the operation handle (3) must be located on a side surface opposite to the side surface on which the movable-portion-side arm is mounted.
In a seat arrangement having a great clearance between seats such as a separate-type seat arrangement, both of the movable-portion-side arm of the reclining device (4) and the operation handle (3) of the lumbar support device can be installed in their respective suitable positions without presenting any interfering problems. However, when a seat is located near the interior walls of a vehicle or when both seat backs for driver's and assistant driver's seats are structured integrally with each other, for example, in case of a split seat, bench seat, dual seat, divided seat or the like, or when the peripheral side faces of the seat backs of both the driver's and assistant driver's seats adjacent to each other are located very near to each other, there is almost no room to mount an operation handle for the lumbar support device. For this reason, in these types of seats, it has been impossible to mount the lumbar support device. Even when an operation handle could be installed onto the side faces of the seat backs having a narrow clearance between them, the operability of this handle greatly decreases because of its interference with an adjacent seat back.